共查询到19条相似文献,搜索用时 125 毫秒
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测量了Tm3+和Ho3+离子的吸收谱以及Cr3+离子在YAG单晶光纤中的R荧光线的寿命.用Dexter理论讨论了Cr3+离子的能量转移效率。结果表明Cr3+→Tm3+的能量转移效率比Cr3+→Ho3+的大. 相似文献
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研究了氟化物玻璃中 Yb3 + 敏化 Pr3 + 、 Tm 3 + 、 Er3 + 或 Ho3 + 产生的上转换发光. 在波长为880nm光的激发下, Yb3 + 敏化 Pr3 + 产生波长为482 ,520 ,529 ,605 和635nm 的荧光. 用波长为970nm 的光激发,在 Yb3 + 敏化作用下, Tm3 + 产生波长为478 , 649 和793nm 的上转换发光; Er3 + 产生波长为547 和525nm 的绿光; Ho3 + 产生543nm 的绿光 相似文献
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上转换氟化物光纤激光器 总被引:1,自引:0,他引:1
氟化物玻璃是一种性能优异的激光基质材料。本文介绍了稀土离子上转换发光的机理和光纤顺的基本结构,综述了近几年来对掺Tm^3+、Pr^3+、Er^3+、Ho^3+和Nd^3+的上转换氟化物光纤激光器的研究和应用概况。 相似文献
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研究了氟化物玻璃中Yb^3+敏化Pr^3+、Tm^3+、Er^3+和Ho^3+产生的上转换发光,在波长为880nm光的激发下,Yb^3+敏化Pr^3+产生波长为482,520,529,605和635nm的荧光。 相似文献
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不同稀土元素掺杂对钛酸钡陶瓷导电性的影响 总被引:4,自引:1,他引:3
采用溶胶-凝胶法制备了14种稀土掺杂的BaTiO3超细粉体(RE=Y,La,Ce,Pr,Nd,Sm,Eu,Gd,Tb,Dy,Ho,Er,Yb,Lu),用一般陶瓷工艺将这些超细粉体分别烧成了14种稀土掺杂的BaTiO3陶瓷,测得了这些陶瓷体的电阻率并对Eu和Yb掺杂的BaTiO3陶瓷成绝缘体的原因进行了初步讨论。 相似文献
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测试了2at.%Er:YAG晶体的吸收谱,荧光谱,4I11/2、4I13/2态荧光衰减曲线.由荧光衰减曲线拟合得到荧光寿命τ0和描述离子间的相互作用微参量CDA,并将其代入作者推导得到的最佳掺杂浓度的近似式,计算出Er3+离子在YAG晶体中的最佳掺杂浓度,并与实验结果进行了比较 相似文献
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采用溶胶-凝胶法制备了稀土氧化物RE2O3(RE=Dy,Ho,Er,Y)掺杂的Li2SiO3离子导体材料,并用DTA、XRD、TEM及交流阻抗仪等技术对样品的结构、形貌、粒径及离子导电性等进行了观察和测试。结果发现,0.1RE2O3的掺入可提高Li2SiO3的离子导电性。 相似文献
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Lalgudi Venkataraman Ramanathan Marina F. Pillis Stela Maria C. Fernandes 《Journal of Materials Science》2008,43(2):530-535
Rare earths (RE) have been used to increase high temperature oxidation resistance of chromia and alumina forming alloys. The
RE can be added as elements (or oxides) to the alloys or applied as oxide coatings to the alloy surface. This paper presents
the effect of different RE oxide coatings and lanthanum chromite coatings on the high temperature oxidation behavior of Fe20Cr
and Fe20Cr4Al alloys. The oxidation resistance of the Fe20Cr alloy increased with increase in ionic radius of the RE element
in the coating. The RE oxides decreased chromia growth rate more than alumina growth rate. In extended cyclic oxidation tests
that were carried out from peak temperatures of 900 °C, 1,000 °C and 1,100 °C to room temperature at cooling rates of 300 °C/s
and 1,000 °C/s, the La2O3 coating increased cyclic oxidation resistance of the Fe20Cr alloy significantly more than the Pr2O3 coating. The role of RE in increasing overall oxidation resistance of chromia forming alloys is discussed. 相似文献
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Single crystals of LaMgAl11O19 (LMA) coactivated with Ce3+, Nd3+ or Ce3+, Cr3+, Nd3+, have been grown by the Verneuil (flame-fusion) method. In LMA:Ce, Nd the Ce → Nd energy transfer occurs both radiatively
and non-radiatively. The efficiency of the non-radiative Ce → Nd transfer reaches ∼47%, as deduced from Ce3+ fluorescence lifetime measurements. In LMA:Ce, Cr, Nd, besides the Ce → Nd energy transfer, Ce → Cr and Cr → Nd transfers
occur. The Ce → Cr energy transfer is highly efficient. This results from the good resonance between Ce emission and Cr absorption,
and also from the short Ce-Cr distance compared to the longer Ce-Nd one. 相似文献
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用高温熔融法制备了Bi、Tm、Bi/Tm掺杂TiO2-BaO-SiO2-Ga2O3玻璃系统。在808 nm激光激发下, 与Tm单掺杂玻璃相比, Bi/Tm共掺玻璃中Tm3+的3H4→3F4跃迁荧光(~1485 nm)得到了显著的增强, 而Tm3+的3F4→3H6跃迁荧光(~1810 nm)减弱。在980 nm激光激发下, Tm单掺玻璃中没有观察到Tm离子的特征发光, 而在Bi/Tm共掺玻璃中观察到Tm3+的3F4→3H6跃迁荧光(~1810 nm)。这是由于在808和980 nm激光二极管(LD)各自激发下, Bi/Tm共掺玻璃中活性Bi离子的近红外发光能量传递给Tm3+, 分别产生3F4→3H4与3H6→3H5跃迁所致。采用Inokuti-Hirayama模型, 分析了该玻璃体系中Bi→Tm的能量传递机理。结果表明, Bi→Tm的能量传递属于电偶极–偶极相互作用。 相似文献
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(Cr,Tm,Ho):YAG晶体中Tm~(3+)离子的中介能量转移作用 总被引:2,自引:0,他引:2
测定了晶体的吸收谱,荧光谱和荧光寿命,用Taylor和Dexter理论计算了Cr3+-Ho3+,Cr3+-Tm3+和Tm3_-Ho3+离子间能量转移效率和转移几率.讨论了(Cr,Tm.Ho):YAG晶体中Tm3+的能量转移中介作用. 相似文献
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《Materials Science & Technology》2013,29(9):918-924
AbstractBy modifying 13Cr–4Mn (wt-%) white cast iron with boron and rare earth (RE)–Si complex, the carbide morphology of the iron can be changed from interconnected, coarse clusters of rods into a parallel distribution of isolated, fine rods, and the impact toughness of the iron can reach 6–7 × 104 J m?2. In a pin wear test, the relative abrasion resistance of the iron is 1·01 and in a repeated impact abrasive wear test it is 0·95, in comparison with 15Cr–3Mo cast iron. Thus, it is stated that modifying high Cr–Mn cast iron with boron and RE–Si complex is very cost effective, and has almost the same abrasion resistance, when compared with 15Cr–3Mo cast iron.MST/957 相似文献
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ZG85Cr12MoNi是一种耐磨性能优良的合金钢,但其组织中共晶碳化物量较多,脆性较大,应用于承受冲击的工况下易发生断裂,为提高其抗断裂能力,研究了钾、钠、稀土和钛复合变质处理对其组织和性能的影响。结果表明,ZG85Cr12MoNi经钾、钠、稀土和钛复合变质处理后,组织细化,共晶碳化物由条块状变成团球状且分布均匀,冲击韧性和断裂韧性大幅度提高,热疲劳性能也明显改善;作轧机导卫板用使用安全,寿命比高铬铸铁和高镍铬合金分别提高300%和35.6%。 相似文献
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The low carbon energy transition has attracted worldwide attention to mitigate climate change. Renewable energy (RE) is the key to this transition, with significant developments to date, especially in China. This study systematically reviews the literature on RE development to identify a general context from many studies. The goal is to clarify key questions related to RE development from the current academic community. We first identify the forces driving RE development. Thereafter, we analyze methods for modeling RE developments considering the systematic and multiple complexity characteristics of RE. The study concludes with insights into the target selection and RE development roadmap in China. 相似文献